In recent years, a discussion on next generation radio communication technologies has been performed to further enhance high-speed, high-capacity radio communication, and the like in a radio communication system such as a portable phone system (cellular system). For example, a communication standard referred to as Long Term Evolution (LTE) and a communication standard referred to as LTE-Advanced (LTE-A) that is based on an LTE radio communication technology have been proposed by 3rd Generation Partnership Project (3GPP) for standardization.
A communication standard recently completed in 3GPP is Release 10 corresponding to LTE-A, in which Release 8 and Release 9 that correspond to LTE are greatly enhanced functionally. At present, a discussion on a main portion of Release 11 that is a further extension of Release 10 has been finished, and details are going to be discussed toward completion of Release 11. In addition, a discussion on Release 12 has started. “LTE” is hereinafter defined as including LTE and LTE-A, and other radio communication systems that are extension of those, unless otherwise specified.
Various technologies are included in 3GPP Release 11, and among them is machine type communication (MTC). MTC is equivalent to so-called machine-to-machine (M2M) communication in 3GPP, and indicates a type of communication in which machines exchange information without a human being involved. Note that the term device-to-device (D2D) communication is used in 3GPP in some cases, and this also indicates the same concept as that of MTC or M2M communication. Moreover, in 3GPP, broad concepts, such as short-distance communication between radio terminals, and services or applications relating to this short-distance communication, are referred to as proximity services (ProSe).
Specific application examples of MTC include monitoring of meters, such as an electricity meter, a gas meter, and a water meter, security monitoring, monitoring of various apparatuses, a sensor network, and the like. Furthermore, it is also assumed that, for example, electric appliances and the like within a house may support MTC, and thus the electric appliances operate in conjunction with each another. A discussion on MTC has lately started in 3GPP, but because it is considered that MTC has applications in many fields, it is expected that the discussion on MTC as a promising technology will continue actively in 3GPP.